JP4985772B2 - Optical subassembly manufacturing method and optical subassembly - Google Patents

Description

  The present invention relates to an optical subassembly manufacturing method applied to an optical interconnect of a server system or a network device, an optical subassembly, an optical interconnect device to which the optical subassembly is applied, a WDM oscillator, and a receiving circuit.

  In an optical interconnect that transmits data in parallel between chips, boards, or racks using an optical fiber group, a transmitter optical subassembly (TOSA) that converts an electrical signal into an optical signal, or an optical signal A receiving optical subassembly (ROSA: Receiver Optical SubAssembly) is used (see, for example, Patent Documents 1 to 5 below).

  FIG. 26 is a perspective view showing an optical interconnect module. As shown in FIG. 26, the optical interconnect module 2610 is a connection module for connecting the boards 2620 with an optical fiber 2630. The optical interconnect module 2610 includes an optical transmission module 2640 and an optical reception module 2650.

  The optical transmission module 2640 includes a transmission circuit 2641 and an optical subassembly 2642. The transmission circuit 2641 outputs an electrical signal based on the data signal transmitted from the circuit element of the board 2620 to the optical subassembly 2642. The optical subassembly 2642 includes a laser diode (LD), and is a TOSA that emits an optical signal based on the electrical signal output from the transmission circuit 2641 via the optical fiber 2630.

  The optical reception module 2650 includes an optical subassembly 2651 and a reception circuit 2652. The optical subassembly 2651 is a ROSA that includes a PD (Photo Detector) and outputs an electrical signal based on the optical signal received through the optical fiber 2630 to the receiving circuit 2652. The receiving circuit 2652 demodulates the electrical signal output from the optical subassembly 2651 into a data signal, and outputs the demodulated data signal to the circuit element of the board 2620.

  FIG. 27 is a front sectional view showing a conventional optical subassembly. As shown in FIG. 27, a conventional optical subassembly 2700 includes a photoelectric conversion element 2720 such as an LD disposed on a wiring board 2710, and a metal cap 2730 that hermetically seals the photoelectric conversion element 2720. . The wiring board 2710 is provided with lead pins and the like that are connected to the photoelectric conversion elements. The metal cap 2730 is provided with a lens member 2740.

  When the photoelectric conversion element 2720 is an LD, the optical subassembly 2700 emits an optical signal generated by the LD via the lens member 2740. When the photoelectric conversion element 2720 is a PD, the optical subassembly 2700 receives an optical signal incident through the lens member 2740 by the PD. Further, a ferrule for connecting an optical fiber or the like is attached to the metal cap 2730.

  FIG. 28 is a front sectional view showing optical axis alignment of a conventional optical subassembly. In FIG. 28, reference numeral 2721 indicates the optical axis of the photoelectric conversion element 2720. Reference numeral 2741 indicates the optical axis of the lens member 2740. In the conventional optical subassembly 2700, in order to improve the optical characteristics, the lens member 2740 is positioned with respect to the photoelectric conversion element 2720 arranged on the wiring board 2710 so that the optical axis 2721 and the optical axis 2741 coincide. .

  When the photoelectric conversion element 2720 is an LD, an optical signal emitted from the LD and passed through the lens member 2740 is monitored, and the lens member 2740 is positioned so that the intensity of the monitored optical signal is maximized. When the photoelectric conversion element 2720 is a PD, an electric signal output from the PD is monitored based on an optical signal incident through the lens member 2740, and the lens member 2740 has a maximum intensity of the monitored electric signal. Positioning.

  With the lens member 2740 positioned, the metal cap 2730 is fixed to the wiring board 2710 by a method such as welding. Accordingly, the photoelectric conversion element 2720 is hermetically sealed by the wiring board 2710 and the metal cap 2730. The space in which the photoelectric conversion element 2720 is hermetically sealed is, for example, a cylindrical shape having a diameter of 5 to 6 mm and a height of 5 to 6 mm.

  Further, when positioning the photoelectric conversion element 2720 with respect to the wiring board 2710, the electrodes of the photoelectric conversion element 2720 are arranged on the solder bumps arranged on the wiring board 2710, and the solder bumps are heated and melted to melt. A self-alignment effect is used in which the photoelectric conversion element 2720 is positioned in a self-aligned manner with respect to the wiring board 2710 due to the surface tension of the solder bump (see, for example, Non-Patent Document 1 below).

JP-A-2005-338408 JP 11-345955 A JP-A-9-197158 JP-A-7-209558 Japanese Patent Laid-Open No. 5-134137

Junichi Sasaki Masataka Ito Nobuhiro Motoyoshi Nobunobu Kanayama, “Self-alignment mounting of optical elements by AuSn bump bonding”, vol. 93, The Institute of Electronics, Information and Communication Engineers, December 1993, p. 61-p. 66

  However, in the above-described conventional technology, the metal cap 2730 for hermetically sealing the photoelectric conversion element 2720 is necessary, and since the joint portion between the lens member 2740 and the metal cap 2730 exists, the optical subassembly 2700 is increased in size ( For example, there is a problem that the diameter is 5 mm × the height is 5 mm. For this reason, for example, there is a problem that it is not possible to satisfy a mounting density required for an optical interconnect (for example, an array with an interval of 0.25 mm).

  Further, since it is necessary to position the lens member 2740 while monitoring the output signal of the photoelectric conversion element 2720, it takes time to position the lens member 2740, and it takes time to manufacture the optical subassembly 2700. Further, since a monitor device that monitors the output signal of the photoelectric conversion element 2720 and a positioning device that positions the lens member 2740 are required, there is a problem that the manufacturing cost of the optical subassembly 2700 increases.

  The present invention solves the above-described problems, and provides a method of manufacturing an optical subassembly, an optical subassembly, and the light capable of reducing the cost of the optical subassembly while reducing the size of the optical subassembly. An object of the present invention is to provide an optical interconnect device, a WDM oscillator, and a receiving circuit to which a subassembly is applied.

  The optical subassembly manufacturing method according to the present invention includes a forming step of forming a connection electrode and a convex refractory glass on a wiring board by determining relative positions of each other, and positioning a photoelectric conversion element on the connection electrode A positioning step for connecting, a disposing step for disposing a low melting point glass having a melting point lower than that of the high melting point glass on the high melting point glass, and a protrusion and a lens portion having a shape matched to the high melting point glass. The projection of the lens member, the relative position of the projection and the optical axis of the lens of which is determined according to the relative position of the connection electrode and the high melting point glass, is disposed on the low melting point glass. A fixing step of fixing the lens member, wherein the lens member is positioned with respect to the high melting point glass by melting the low melting point glass.

  According to the above configuration, the lens member can be automatically and accurately positioned at high speed with respect to the wiring board and the high melting point glass by utilizing the self-alignment effect resulting from the surface tension of the molten low melting point glass. For this reason, the manufacturing time of an optical subassembly can be shortened.

  Further, in the forming step, the high melting point glass is formed in an annular shape surrounding the connection electrode, and the protrusion of the lens member is formed in an annular shape matching the high melting point glass, and in the fixing step, the wiring board is formed. The photoelectric conversion element is hermetically sealed by the high melting point glass, the low melting point glass, and the lens member.

  According to the said structure, a photoelectric conversion element can be airtightly sealed with a lens member, without using a metal cap by forming the projection part of a lens member, high melting glass, and low melting glass in the annular | circular shape surrounding a connection electrode. For this reason, an optical subassembly can be reduced in size.

  According to the present invention, it is possible to reduce the cost of the optical subassembly while reducing the size of the optical subassembly.

1 is a front sectional view showing an optical subassembly according to a first embodiment; FIG. 3 is a partially transmissive plan view showing a wiring board and an LD of the optical subassembly according to the first embodiment. FIG. 3 is a partially transparent plan view showing a lens member of the optical subassembly according to the first embodiment. 4 is a flowchart showing an example of a manufacturing process of the optical subassembly according to the first embodiment. It is process drawing corresponding to step S401 of FIG. FIG. 5 is a process diagram (part 1) corresponding to steps S402 and S403 in FIG. 4; FIG. 6 is a process diagram (part 2) corresponding to steps S402 and S403 in FIG. 4; FIG. 6 is a process diagram (part 3) corresponding to steps S402 and S403 in FIG. 4; FIG. 6 is a process diagram (part 4) corresponding to steps S402 and S403 in FIG. 4; FIG. 5 is a process diagram (part 1) corresponding to step S404 in FIG. 4; FIG. 6 is a process diagram (part 2) corresponding to step S404 in FIG. 4; FIG. 6 is a process diagram (part 3) corresponding to step S404 in FIG. 4; It is process drawing corresponding to step S405 of FIG. It is process drawing corresponding to step S406 and S407 of FIG. FIG. 5 is a process diagram corresponding to step S408 in FIG. 4. FIG. 6 is a front sectional view showing an optical subassembly according to a second embodiment. FIG. 6 is a partially transmissive plan view showing a wiring board and an LD of an optical subassembly according to a second embodiment. FIG. 6 is a partially transmissive plan view showing a lens member of the optical subassembly according to the second embodiment. 6 is a flowchart illustrating an example of a manufacturing process of an optical subassembly according to a second embodiment; FIG. 20 is a process diagram corresponding to steps S1906 and S1908 in FIG. 19. It is front sectional drawing which shows the OSA array concerning Example 1 of this invention. It is front sectional drawing which shows the device for optical interconnects concerning Example 2 of this invention. It is front sectional drawing which shows the WDM oscillator concerning Example 3 of this invention. It is a schematic plan view which shows the receiving circuit concerning Example 4 of this invention. It is front sectional drawing which shows the receiving circuit concerning Example 4 of this invention. It is a perspective view which shows an optical interconnect module. It is front sectional drawing which shows the conventional optical subassembly. It is front sectional drawing which shows the optical axis alignment of the conventional optical subassembly.

  Exemplary embodiments of an optical subassembly manufacturing method and an optical subassembly according to the present invention will be explained below in detail with reference to the accompanying drawings.

(Embodiment 1)
FIG. 1 is a front sectional view showing an optical subassembly according to the first embodiment. The optical subassembly 100 according to the first embodiment is a TOSA that generates and emits an optical signal corresponding to an input electrical signal. As shown in FIG. 1, the optical subassembly 100 includes a wiring substrate 110, connection electrodes 120, solder bumps 130, a high melting point glass 140, a low melting point glass 150, an LD 160, and a lens member 170. ing.

  Wiring substrate 110 is a ceramic substrate such as alumina (aluminum oxide). The connection electrode 120 is an electrode that connects the wiring substrate 110 and the LD 160, and is formed on the wiring substrate 110. The solder bump 130 (second low melting point member) has a melting point lower than that of the connection electrode 120 and is disposed on the connection electrode 120. The solder bump 130 is an alloy of gold and tin (solder metal).

  The high melting point glass 140 (high melting point member) is formed in a convex shape on the wiring substrate 110. The refractory glass 140 is formed on the wiring board 110 at a position relative to the wiring board 110. The high melting point glass 140 is, for example, silica glass. The low melting point glass 150 (low melting point member) is a glass member having a lower melting point than the high melting point glass 140. The low melting point glass 150 is disposed on the high melting point glass 140. The low melting point glass 150 is a silica glass to which impurities such as phosphorus and boron are added.

  The LD 160 (photoelectric conversion element) is connected to the connection electrode 120 via the solder bump 130. The LD 160 includes a light emitting unit 161 and an electrode 162 that transmits an electric signal to the light emitting unit 161. The electrode 162 of the LD 160 is disposed on the solder bump 130. The LD 160 is hermetically sealed by the wiring substrate 110, the high melting point glass 140, the low melting point glass 150, and the lens member 170.

  The lens member 170 includes a protrusion 171 and a lens portion 172 that are shaped to match the high melting point glass 140. The shape of the protrusion 171 matched to the high melting point glass 140 is a shape in which the shapes of the joint surfaces of the protrusions 171 substantially coincide with each other when the protrusion 171 is disposed on the high melting point glass 140. In particular, by forming the protrusion 171 in a shape that completely matches the shape of the joint surface, the positioning accuracy by the self-alignment effect described later can be enhanced.

  For example, the refractory glass 140 and the protrusion 171 are formed in an annular shape with the same radius, and the joint surfaces thereof are circular with the same radius. In addition, the lens member 170 is fixed to the high melting point glass 140 and the wiring substrate 110 with the protrusions 171 disposed on the low melting point glass 150. The lens member 170 is bonded to the high melting point glass 140 in a state where the lens member 170 is positioned with respect to the high melting point glass 140 by a self-alignment effect caused by melting the low melting point glass 150.

  In addition, by forming the lens member 170 including the protruding portion 171 and the lens portion 172 with an integral transmission member, the protruding portion 171 can also have light transmittance. For the lens member 170, a transmissive member having a higher melting point than the low-melting glass 150 (for example, a melting point similar to that of the high-melting glass 140) is used. The optical axis 173 of the lens portion 172 of the lens member 170 coincides with the optical axis 163 of the light emitting portion 161 of the LD 160.

  FIG. 2 is a partially transparent plan view showing the wiring board and LD of the optical subassembly according to the first embodiment. 1 is a cross-sectional view taken along the line AA 'of FIG. As shown in FIG. 2, the light emitting unit 161 is provided on the front surface of the LD 160, and four electrodes 162 are provided on the back surface of the LD 160. The four electrodes 162 are provided at the four corners of the back surface of the LD 160 so that the distances from the optical axis 163 of the light emitting unit 161 are equal to each other.

  Four connection electrodes 120 are formed on the wiring substrate 110. The four connection electrodes 120 are formed at positions corresponding to the four electrodes 162, and are joined to the electrodes 162 of the LD 160 via the solder bumps 130, respectively. The high melting point glass 140 is formed in an annular shape (donut type) surrounding the connection electrode 120 on the wiring substrate 110.

  The refractory glass 140 is formed in an annular shape (having a radius of r) with the center point of the four connection electrodes 120 as the center. Since the optical axis 163 of the LD 160 connected to the connection electrode 120 passes through the center point of the four connection electrodes 120, the refractory glass 140 is formed in an annular shape centering on the optical axis 163 of the LD 160.

  Here, the shape of the four electrodes 162 of the LD 160 is a shape matched to the four connection electrodes 120 respectively. The four electrodes 162 of the LD 160 are joined in a state of being positioned with respect to the four connection electrodes 120 by a self-alignment effect caused by melting the four solder bumps 130.

  FIG. 3 is a partially transparent plan view illustrating the lens member of the optical subassembly according to the first embodiment. As shown in FIG. 3, the lens portion 172 of the lens member 170 is provided on the front surface of the lens member 170, and the protrusion 171 is provided on the back surface of the lens member 170. The protrusion 171 of the lens member 170 is formed in an annular shape that matches the refractory glass 140. Further, the relative position between the projection 171 of the lens member 170 and the optical axis 173 is determined according to the relative position between the connection electrode 120 and the refractory glass 140.

  Here, since the refractory glass 140 has an annular shape (see FIG. 2) with a radius r centering on the center point of the four connection electrodes 120, the protrusion 171 of the lens member 170 is the optical axis 173 of the lens member 170. Is formed in an annular shape with a radius r centering on. For this reason, the high melting point glass 140 and the projection 171 of the lens member 170 are joined to each other so that the optical axis 163 of the light emitting unit 161 passing through the center point of the four connection electrodes 120 and the lens unit 172 The optical axis 173 matches.

  FIG. 4 is a flowchart of an example of the manufacturing process of the optical subassembly according to the first embodiment. As shown in FIG. 4, first, the connection electrode 120 is formed at a position on the wiring board 110 where the electrode 162 of the LD 160 is disposed (step S401). Next, the relative position with respect to the connection electrode 120 formed by step S401 is determined, and the high melting glass 140 is formed on the wiring board 110 (step S402).

  Next, the low melting point glass 150 is placed on the high melting point glass 140 formed in step S402 (step S403). Next, the solder bump 130 is disposed on the connection electrode 120 formed in step S401 (step S404). Next, LD160 is arrange | positioned on the solder bump 130 arrange | positioned by step S404 (step S405).

  Next, the LD 160 is positioned with respect to the wiring board 110 by melting the solder bumps 130 (step S406). Next, the LD 160 is fixed to the wiring board 110 by cooling the solder bump 130 (step S407). Next, the lens member 170 is disposed on the low melting point glass 150 disposed in step S403 (step S408).

  Next, the lens member 170 is positioned with respect to the wiring board 110 by melting the low melting point glass 150 (step S409). Next, the lens member 170 is fixed to the wiring board 110 by cooling the low melting point glass 150 (step S410), and the manufacturing process of the series of optical subassemblies 100 is completed.

  FIG. 5 is a process diagram corresponding to step S401 in FIG. Here, four connection electrodes 120 are formed at positions on the wiring board 110 corresponding to the four electrodes 162 of the LD 160. 6 to 9 are process diagrams (part 1) to (part 4) corresponding to steps S402 and S403 in FIG. First, as shown in FIG. 6, a layer of a high melting point glass 140 and a layer of a low melting point glass 150 are sequentially formed on the wiring substrate 110 by a chemical vapor deposition method or the like.

  Next, as shown in FIG. 7, a photoresist 710 is patterned in an annular shape on the low melting point glass 150 such that the relative position between the high melting point glass 140 after etching and the connection electrode 120 is the position described above. Next, as shown in FIG. 8, a portion of the high melting point glass 140 and the low melting point glass 150 where the photoresist 710 is not patterned is removed by a chemical ion etching method or the like.

  Next, as shown in FIG. 9, the photoresist 710 is removed by ashing and cleaning using enzyme plasma. As a result, the high melting point glass 140 and the low melting point glass 150 are formed on the wiring substrate 110. 10 to 12 are process diagrams (part 1) to (part 3) corresponding to step S404 in FIG. As shown in FIG. 10, a photoresist 1010 is patterned on the surface of the wiring substrate 110 except for the connection electrodes 120.

  Next, as shown in FIG. 11, a layer of solder metal 130a is formed by a vacuum evaporation method or the like. Next, as shown in FIG. 12, the photoresist 1010 and the solder metal 130a on the photoresist 1010 are removed by a lift-off method or the like infiltrated with an organic solvent such as acetone. Thus, the solder metal 130a remaining on the connection electrode 120 will be described as the solder bump 130.

  FIG. 13 is a process diagram corresponding to step S405 in FIG. As shown in FIG. 13, the electrode 162 of the LD 160 is disposed on the solder bump 130. In this step, the electrode 162 of the LD 160 does not need to be accurately positioned on the solder bump 130, and the electrode 162 may be on the solder bump 130.

  FIG. 14 is a process diagram corresponding to steps S406 and S407 of FIG. In step S406, for example, the wiring board 110 and the entire element on the wiring board 110 are heated to about 300 ° C. to melt only the solder bumps 130. In this case, the melting points of all elements except the solder bumps 130 are set higher than 300 ° C. When the solder bump 130 is melted, the electrode 162 of the LD 160 is uniquely positioned with respect to the connection electrode 120 by a self-alignment effect caused by the surface tension of the melted solder bump 130 as shown in FIG.

  For this reason, the LD 160 can be positioned at a predetermined position on the wiring board 110. Next, the molten solder bump 130 is cooled and solidified, so that the LD 160 can be fixed while being positioned on the wiring board 110. The molten solder bump 130 is cooled by, for example, natural cooling.

  FIG. 15 is a process diagram corresponding to step S408 in FIG. As shown in FIG. 15, the protrusion 171 of the lens member 170 is disposed on the low melting point glass 150. In this step, the protrusion 171 does not need to be accurately positioned on the low-melting glass 150, and the protrusion 171 may be on the low-melting glass 150.

  The process diagram corresponding to steps S409 and S410 in FIG. 4 is the same as that in FIG. In order to melt the low melting glass 150, for example, the low melting glass 150 is irradiated with a laser. For example, a femtosecond laser is used as the laser for irradiating the low melting point glass 150. Thereby, the low melting glass 150 can be heated instantaneously.

  Further, the protrusion 171 of the lens member 170 has a light transmitting property that allows laser to pass therethrough. As a result, as indicated by reference numeral 1510 in FIG. 15, the low-melting glass 150 can be melted by increasing the temperature of the low-melting glass 150 by irradiating the low-melting glass 150 with a laser through the protrusion 171. .

  At this time, by focusing the laser beam on the low-melting glass 150, the temperature of the low-melting glass 150 can be locally increased by a nonlinear light absorption phenomenon (two-photon absorption). Therefore, the low melting point glass 150 can be melted without damaging elements around the low melting point glass 150 such as the solder bump 130, the high melting point glass 140, the LD 160, and the lens member 170.

  For example, the entire low-melting glass 150 can be melted at the same time by irradiating the laser while rotating the laser irradiation device along the ring of the low-melting glass 150. Let Δt be the time until the low-melting glass 150 melted by laser irradiation is solidified again by natural cooling, and T is the period when the laser spot travels around the ring of the low-melting glass 150.

  In this case, laser pulse irradiation energy (10 to 100 nJ / pulse), pulse generation frequency (1 k to 10 k pulse / second), beam moving speed (0.1 to 10 mm) so that the period T is shorter than the time Δt. By controlling / s), the entire low-melting glass 150 can be melted at the same time. Alternatively, a plurality of laser irradiation apparatuses may be prepared, and the plurality of irradiation apparatuses may be rotated along the ring of the low melting point glass 150.

  For example, by providing two irradiation devices at positions separated from each other on the ring of the low melting point glass 150 and rotating them simultaneously, the low melting point glass 150 can be irradiated with the laser twice for each rotation. For this reason, for example, the moving speed of the beam (the rotational speed of the irradiation device) can be halved. Note that laser irradiation of the low-melting glass 150 is preferably performed in a dry nitrogen atmosphere.

  In addition, the laser incident portion 174 in the lens member 170 when the low melting point glass 150 is irradiated with the laser through the protrusion 171 is formed in parallel with the joint surface between the protrusion 171 and the low melting point glass 150. As a result, when the laser is incident on the incident portion 174 perpendicularly, the laser goes straight to the low melting point glass 150, so that the low melting point glass 150 can be accurately irradiated with the laser.

  Further, an antireflective coating may be applied to the surface of the incident portion 174. Thereby, the reflection of the laser beam at the incident portion 174 can be prevented, and the low melting point glass 150 can be efficiently irradiated with the laser beam. Further, the distance between the incident portion 174 and the joint surface of the protrusion 171 with the low melting point glass 150 is formed so as to be equal in each portion of the protrusion 171 formed in an annular shape. This makes it possible to keep the laser beam focal point constant when the low melting point glass 150 is irradiated with the laser while rotating the irradiation device.

  When the low-melting glass 150 is melted, as shown in FIG. 1, the protrusion 171 of the lens member 170 is uniquely formed with respect to the high-melting glass 140 due to the self-alignment effect caused by the surface tension of the melted low-melting glass 150. Positioned. Therefore, the lens member 170 can be positioned at a predetermined position on the wiring board 110, and the optical axis 163 of the LD 160 and the optical axis 173 of the lens member 170 can be matched with high accuracy.

  Next, the lens member 170 can be fixed in a state of being positioned on the wiring board 110 by cooling and solidifying the molten low melting point glass 150. The molten low melting point glass 150 is cooled by, for example, natural cooling. As a result, the LD 160 is hermetically sealed by the wiring substrate 110, the high melting point glass 140, the low melting point glass 150, and the lens member 170.

  As described above, according to the manufacturing method of the optical subassembly 100 and the optical subassembly 100 according to the first embodiment, the lens member 170 is wired using the self-alignment effect caused by the surface tension of the molten low melting point glass 150. The substrate 110 and the refractory glass 140 can be automatically and accurately positioned at high speed. Therefore, the manufacturing time of the optical subassembly 100 can be shortened, and the cost of the optical subassembly 100 can be reduced.

  For example, in the method of manufacturing the optical subassembly 100 according to the first embodiment, the positioning of the lens member 170 and the hermetic sealing of the LD 160 are simultaneously performed by melting the low melting point glass 150. The time required for melting and cooling 150 can be as long as 10 seconds.

  Further, by forming the protrusion 171 of the lens member 170, the high melting point glass 140, and the low melting point glass 150 in an annular shape surrounding the LD 160, the LD 160 can be hermetically sealed by the lens member 170 without using a metal cap. For this reason, the optical subassembly 100 can be reduced in size. Further, the number of joints of the optical subassembly 100 can be reduced, and the optical subassembly 100 can be configured with high accuracy. Further, the number of parts of the optical subassembly 100 can be reduced, and the cost of the optical subassembly 100 can be reduced.

  Further, the projection 171 of the lens member 170 is made light transmissive, and the low melting point glass 150 is irradiated with a laser through the projection 171 so that only the low melting point glass 150 can be easily heated and melted. it can. For this reason, the low melting point glass 150 can be melted without damaging elements around the low melting point glass 150. Since the lens portion 172 has light transmittance as a characteristic of the lens, the projection portion 171 can easily have light transmittance by forming the lens member 170 with an integral transmission member.

  Further, the low melting point glass 150 is formed into an annular shape, and the low melting point glass 150 is irradiated with a laser while rotating the laser irradiation device, whereby the entire low melting point glass 150 can be efficiently heated and melted. . Further, by providing a plurality of laser irradiation devices to be rotated, the entire low melting point glass 150 can be heated and melted more efficiently.

  Further, by forming the connection electrode 120 and the refractory glass 140 by lithography, the relative position of the connection electrode 120 and the refractory glass 140 can be determined with high accuracy. Furthermore, by utilizing the self-alignment effect of the solder bump 130 and the low melting point glass 150, the LD 160 relative to the connection electrode 120 and the lens member 170 relative to the high melting point glass 140 can be positioned with high accuracy. Therefore, the optical axis 163 of the LD 160 and the optical axis 173 of the lens member 170 can be matched easily and with high accuracy, and the optical characteristics of the optical subassembly 100 can be improved.

  For example, the positioning accuracy of the connection electrode 120 and the high melting point glass 140 by lithography is ± 0.1 μm, the positioning accuracy of the LD 160 using the self alignment effect by the solder bump 130 is 0.5 μm or less, and the self alignment effect by the low melting point glass 150 is used. The positioning accuracy of the lens member 170 is 0.5 μm or less, and the alignment accuracy of these combined is ± 1.2 μm at the maximum.

  Thereby, the optical axis adjustment accuracy (for example, ± 2.5 μm or less) required for positioning the optical axis 173 of the lens member 170 and the optical axis 163 of the LD 160 can be satisfied. Further, by using glass members such as the high melting point glass 140 and the low melting point glass 150 for the high melting point member and the low melting point member, the strength and corrosion resistance of the joint portion between the wiring board 110 and the lens member 170 are improved, and the LD 160 Can be stably hermetically sealed.

(Embodiment 2)
FIG. 16 is a front sectional view of the optical subassembly according to the second embodiment. FIG. 17 is a partially transparent plan view showing the wiring board and LD of the optical subassembly according to the second embodiment. 16 and 17, the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof is omitted. 16 is a cross-sectional view taken along the line AA ′ of FIG.

  As shown in FIGS. 16 and 17, four (plurality) of high melting point glasses 140 are formed on the wiring substrate 110 of the optical subassembly 100 according to the second embodiment. Here, the four high melting point glasses 140 are each formed in a cylindrical convex shape. The four refractory glasses 140 are provided on the wiring substrate 110 at equal intervals on the circumference of the radius R around the optical axis 163 of the LD 160. Four low melting point glasses 150 are provided corresponding to the four high melting point glasses 140, and are arranged on the plurality of high melting point glasses 140, respectively.

  In addition to the four high melting point glasses 140, a high melting point glass 1610 (second high melting point member) is formed on the wiring board 110. The high melting point glass 1610 is formed in an annular shape (donut type) surrounding the connection electrode 120 on the wiring substrate 110. The high melting point glass 1610 is formed in an annular shape having a radius r with the center point of the four connection electrodes 120 as the center. The high melting point glass 1610 is made of the same material as the high melting point glass 140, for example.

  Further, the protrusion 1630 of the lens member 170 has a light transmitting property that allows the laser to pass therethrough. For example, by forming the lens member 170 including the protrusion 171, the lens part 172, and the protrusion 1630 with an integral transmission member, the protrusion 171 and the protrusion 1630 can have light transmittance.

  Since the optical axis 163 of the light emitting part 161 of the LD 160 connected to the connection electrode 120 passes through the center point of the four connection electrodes 120, the refractory glass 1610 is a circle centering on the optical axis 163 of the light emitting part 161 of the LD 160. It is formed in an annular shape. On the high melting point glass 1610, a low melting point glass 1620 (third low melting point member) having a melting point lower than that of the high melting point glass 1610 is disposed.

  The low melting point glass 1620 is made of the same material as the low melting point glass 150, for example. Four protrusions 171 of the lens member 170 are provided corresponding to the four high melting point glasses 140. In addition to the four protrusions 171, the lens member 170 has an annular protrusion 1630 (second protrusion) matched to the refractory glass 1610.

  In addition, the lens member 170 is fixed to the wiring substrate 110 in a state where the four protrusions 171 are respectively disposed on the plurality of low melting point glasses 150 and the protrusions 1630 are disposed on the low melting point glass 1620. The lens member 170 is positioned with respect to the high melting point glass 140 by melting the four low melting point glasses 150.

  FIG. 18 is a partially transparent plan view illustrating a lens member of the optical subassembly according to the second embodiment. 18, the same components as those illustrated in FIG. 3 are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG. 18, the lens member 170 has four protrusions 171 corresponding to the four high melting point glasses 140. The four protrusions 171 are formed in a cylindrical convex shape in accordance with the cylindrical convex shape of the high melting point glass 140. Further, the four protrusions 171 are provided at equal intervals on the circumference of the radius R around the optical axis 173 of the lens portion 172.

  The protrusion 1630 of the lens member 170 is formed in an annular shape that matches the refractory glass 1610. Further, the relative position between the protrusion 1630 of the lens member 170 and the optical axis 173 of the lens part 172 is determined according to the relative position between the connection electrode 120 and the refractory glass 140. Here, the protrusion 1630 of the lens member 170 is formed in an annular shape having a radius r with the optical axis 173 of the lens portion 172 of the lens member 170 as the center.

  Thus, the four high melting point glasses 140 and the four protrusions 171 can be aligned by melting the low melting point glass 150. Further, by cooling the melted low melting point glass 150, the four high melting point glasses 140 and the four protrusions 171 can be joined and fixed in a state of being aligned. For this reason, the optical axis 173 of the lens unit 172 and the optical axis 163 of the light emitting unit 161 passing through the center point of the four high melting point glasses 140 coincide with each other.

  Further, by melting and cooling the low melting point glass 1620, the high melting point glass 1610 and the protrusion 1630 of the lens member 170 can be joined and fixed. Thereby, the LD 160 can be hermetically sealed by the wiring substrate 110, the high melting point glass 1610, the low melting point glass 1620, and the lens member 170.

  FIG. 19 is a flowchart of an example of the manufacturing process of the optical subassembly according to the second embodiment. As shown in FIG. 19, first, the connection electrode 120 is formed at a position on the wiring board 110 where the electrode 162 of the LD 160 is disposed (step S1901). The formation of the connection electrode 120 is the same as the process diagram shown in FIG.

  Next, relative positions with respect to the connection electrode 120 formed in step S1901 are determined, and high melting point glasses 140 and 1610 are formed on the wiring board 110 (step S1902). Next, the low melting glass 150 and 1620 are respectively disposed on the high melting glass 140 and 1610 formed in step S1902 (step S1903).

  Specifically, in the process diagrams shown in FIGS. 6 to 9, a photoresist is formed on the low melting point glass 150 so that the relative positions of the connection electrode 120, the high melting point glass 140, and the high melting point glass 1610 are the positions described above. By patterning 710, the high melting point glass 140 and the high melting point glass 1610 can be formed, and the low melting point glass 150 and the low melting point glass 1620 can be arranged.

  Next, the LD 160 is positioned and connected on the connection electrode 120 formed in step S1901 (step S1904). The positioning and connection of the LD 160 are as shown in the process diagrams shown in FIGS. Next, the lens member 170 is disposed on the low melting point glass 150 disposed in step S1903 (step S1905).

  Next, the lens member 170 is positioned with respect to the wiring board 110 by melting the low melting point glass 150 (step S1906). Next, the lens member 170 is fixed to the wiring board 110 by cooling the low melting point glass 150 (step S1907). Next, the low melting point glass 1620 is melted and cooled to join the high melting point glass 1610 and the protrusion 1630 of the lens member 170, and the LD 160 is hermetically sealed (step S1908). The process ends.

  FIG. 20 is a process diagram corresponding to steps S1906 and S1908 of FIG. In step S1906, as shown by reference numeral 2010 in FIG. 20, the low-melting glass 150 is melted by irradiating the low-melting glass 150 with a laser such as a femtosecond laser through the protrusion 171 of the lens member 170.

  Here, four low-melting glasses 150 are provided corresponding to the four high-melting glasses 140, and therefore, the four low-melting glasses 150 are simultaneously applied to these low-melting glasses 150 using four laser irradiation devices. By irradiating with a laser, it becomes easy to melt these low melting glass 150 at the same time. Therefore, it is possible to position the lens member 170 with respect to the wiring board 110 at high speed and with high accuracy.

  In step S1908, as indicated by reference numeral 2020, the low melting glass 1620 is melted by irradiating the low melting glass 1620 with a laser such as a femtosecond laser through the protrusion 1630. Since the low melting point glass 1620 is formed in an annular shape, it can be melted by the same method as the low melting point glass 150 according to the first embodiment described above.

  Here, since the positioning of the lens member 170 has been completed in step S1906, the positioning accuracy is not required in step S1908, and it is sufficient that the LD 160 can be hermetically sealed with the annular low-melting glass 1620. For this reason, the high melting point glass 1630 and the protrusion 1630 of the lens member 170 do not need to be formed as accurately as the high melting point glass 140 and the protrusion 171 of the lens member 170.

  For example, when the protrusion 171 of the lens member 170 is disposed on the low melting point glass 150, the protrusion 1630 may be formed short so that the protrusion 1630 does not contact the low melting point glass 1620. In this case, the protrusion 1630 may not have a shape that matches the low melting point glass 1620 with high accuracy.

  In step S1908, the protrusion 1630 is first irradiated with a laser to melt the protrusion 1630 so that the melted protrusion 1630 hangs down until it contacts the low melting point glass 1620 under its own weight. Next, the LD 160 can be hermetically sealed by irradiating and melting the low melting point glass 1620 with a laser and bonding the low melting point glass 1620 to the protrusion 1630.

  As described above, according to the manufacturing method of the optical subassembly 100 and the optical subassembly 100 according to the second embodiment, the lens member 170 can be obtained with high accuracy by the low-melting glass 150 interspersed with the effects of the first embodiment. Can be positioned, and the LD 160 can be hermetically sealed by the low melting point glass 1620 formed in an annular shape.

  In each of the embodiments described above, the configuration in which the high melting point member is formed on the wiring board 110 by providing the high melting point glass 140 or the like on the wiring board 110 has been described. However, the wiring board 110 itself is made of a high melting point material. For example, the high melting point member may be formed on the wiring board 110 by providing a groove on the wiring board 110 to make a part of the wiring board 110 convex.

  In each of the above-described embodiments, the case where the optical subassembly 100 is configured as TOSA by providing the LD 160 on the connection electrode 120 as a photoelectric conversion element has been described. However, the PD is replaced on the connection electrode 120 instead of the LD 160. By providing, the optical subassembly 100 can be configured as ROSA. In this case, the optical axis 173 of the lens portion 172 of the lens member 170 is made to coincide with the optical axis of the PD (the optical path where the light receiving sensitivity of the PD is highest).

  Moreover, in each embodiment mentioned above, although the structure which uses the high melting glass 140 and the low melting glass 150 as a high melting point member and a low melting point member was demonstrated, a high melting point member and a low melting point member are not restricted to these glass members. . That is, the high melting point member and the low melting point member may be members that have different melting points and can be joined by melting.

  In each of the above-described embodiments, the method of disposing the solder bump 130 on the connection electrode 120 and disposing the electrode 162 of the LD 160 on the solder bump 130 has been described. However, the method of positioning the LD 160 is not limited thereto. . For example, the solder bump 130 may be welded to the electrode 162 of the LD 160 in advance, and the solder bump 130 and the LD 160 may be arranged together on the connection electrode 120.

  In the first embodiment described above, the refractory glass 140 is described as being formed in an annular shape (doughnut shape) surrounding the connection electrode 120 on the wiring substrate 110. However, the shape of the refractory glass 140 is an annular shape. Not limited to. For example, the refractory glass 140 may be an annular rectangle surrounding the connection electrode 120 or an annular ellipse surrounding the connection electrode 120. The same applies to the high melting point glass 1610 according to the second embodiment.

  In Embodiment 1 described above, the method of irradiating the laser while rotating the laser irradiation device along the ring of the low-melting glass 150 has been described. However, the laser irradiation method is not limited to this, and a plurality of laser irradiation methods are used. Irradiation devices may be arranged along the ring of the low-melting glass 150, and the entire low-melting glass 150 may be irradiated with the laser simultaneously. The same applies to the low melting point glass 1620 according to the second embodiment.

  Moreover, in Embodiment 2 mentioned above, although the structure which provides the projection part 171 of 4 each of the high melting glass 140, the low melting glass 150, and the lens member 170 was demonstrated, these are not restricted to 4 each. For example, when the refractory glass 140 is a cylinder, the lens member 170 can be positioned by the self-alignment effect by providing at least two of each. The same applies to the connection electrode 120, the solder bump 130, and the electrode 162 of the LD 160 of each embodiment.

  Further, in Embodiment 2 described above, the method of irradiating laser to these low melting glass 150 using four laser irradiation devices corresponding to the low melting glass 150 has been described. However, the present invention is not limited to this, and the four low-melting glasses 150 may be melted simultaneously by sequentially irradiating the four low-melting glasses 150 with laser while moving one irradiation device.

Example 1
FIG. 21 is a front sectional view showing the OSA array according to Example 1 of the present invention. An optical subassembly (OSA) array 2100 according to Example 1 of the present invention is an example in which a plurality of optical subassemblies 100 according to Embodiment 1 of the present invention are arranged in an array. As shown in FIG. 21, the OSA array 2100 includes a plurality of optical subassemblies 100, guide pins 2110, ferrules 2120, and a plurality of optical fibers 2130.

  As described above, the plurality of optical subassemblies 100 include the LD 160 and are configured as TOSA. The plurality of optical subassemblies 100 are arranged in an array, and the respective wiring boards 110 are integrally formed. The plurality of optical subassemblies 100 are positioned with respect to the wiring board 110 using the self-alignment effect described above.

  The guide pins 2110 fix the ferrule 2120 to the wiring substrate 110 that is configured integrally with the plurality of optical subassemblies 100. The ferrule 2120 positions the plurality of optical fibers 2130 on the respective optical axes 173 of the lens members 170 of the plurality of optical subassemblies 100. Ferrule 2120 is, for example, an MT (Mechanically Transferable) ferrule.

  The optical subassembly 100 emits the optical signal generated by the LD 160 through the optical fiber 2130. Further, in the case where a PD is provided instead of the LD 160 and the optical subassembly 100 is configured as ROSA, the optical subassembly 100 converts an optical signal received through the optical fiber 2130 into an electrical signal.

  According to the OSA array 2100 according to the first embodiment of the present invention, the size of the optical subassembly 100 can be set to about 0.2 mm (diameter) × 0.2 mm (height). Therefore, a plurality of optical subassemblies 100 can be mounted in an array at intervals of 0.25 mm, for example, and the mounting density required for the optical interconnect can be satisfied.

(Example 2)
FIG. 22 is a front sectional view showing an optical interconnect device according to the second embodiment of the present invention. In the optical interconnect device 2200 according to the second embodiment of the present invention, the optical subassembly 100 according to the first embodiment of the present invention is applied to an optical interconnect device that transmits an optical signal by spatial propagation on a chip or a board. This is an example. As shown in FIG. 22, the optical interconnect device 2200 includes a TOSA 2210 and a ROSA 2220.

  The TOSA 2210 has a configuration in which the lens member 170 is deformed in the optical subassembly 100 according to the first embodiment. The lens member 170 includes a reflection mirror 2211 that reflects light emitted vertically from the LD 160 at a right angle. Further, the lens portion 172 of the lens member 170 is provided at a position where light emitted from the LD 160 and reflected by the reflection mirror 2211 is allowed to pass.

  The optical axis 173 of the lens unit 172 coincides with the optical path 2212 (predetermined optical path) of the light emitted from the LD 160 and reflected by the reflection mirror 2211. Thereby, the light emitted from the LD 160 is emitted from the lens unit 172 so as to be horizontal to the wiring board 110. The TOSA 2210 and the ROSA 2220 are mounted in the horizontal direction, and the respective wiring boards 110 are integrally formed.

  The ROSA 2220 has a configuration in which the lens member 170 is deformed in the optical subassembly 100 according to the first embodiment, and a PD 2221 is provided instead of the LD 160. The lens portion 172 of the lens member 170 in the ROSA 2220 is provided at a position that allows light emitted horizontally from the TOSA 2210 to pass therethrough. The optical axis 173 of the lens unit 172 coincides with the optical path 2212 of the light emitted horizontally from the TOSA 2210.

  The lens member 170 includes a reflection mirror 2222 that totally reflects light that has passed through the lens portion 172 at a right angle. The reflection mirror 2222 is provided at a position where the optical axis 2223 of the reflected light coincides with the optical axis of the PD 2221. Thereby, the light emitted horizontally from the TOSA 2210 is received by the PD 2221. Therefore, the optical interconnect device 2200 can transmit an optical signal from the TOSA 2210 to the ROSA 2220 by spatial transmission.

  According to the optical interconnect device 2200 according to the second embodiment of the present invention, the size of the optical subassembly 100 can be set to about 0.2 mm (diameter) × 0.2 mm (height). Therefore, a plurality of optical subassemblies 100 can be mounted in an array at intervals of, for example, 0.25 mm, and the mounting density required for the optical interconnect device can be satisfied. Further, since the LD 160 and the lens member 170 of the TOSA 2210 and the ROSA 2220 can be accurately positioned with respect to the wiring board 110, the light transmission accuracy can be improved.

Example 3
FIG. 23 is a front sectional view showing a WDM oscillator according to the third embodiment of the present invention. A wavelength division multiplexing (WDM) oscillator 2300 according to a third embodiment of the present invention generates a plurality of lights having different wavelengths and multiplexes the generated lights and emits the multiplexed light. 3 is an example in which the optical subassembly 100 according to the first embodiment is applied.

  As shown in FIG. 23, the WDM oscillator 2300 includes a plurality of TOSAs 2310, 2320, 2330, 2340, and a reflection member 2350. The plurality of TOSAs 2310, 2320, 2330, and 2340 emit optical signals having wavelengths λ1 to 4 respectively. The TOSA 2310 has a configuration in which the LD 160 oscillates light having a wavelength λ1 in the TOSA 2210 described above.

  The TOSA 2310 emits an optical signal of λ1 to the TOSA 2320. The TOSA 2310, 2320, 2330, and 2340 are mounted in the horizontal direction, and the respective wiring boards 110 are integrally formed. In the TOSA 2320, the reflection mirror 2211 is a wavelength selection mirror in the above-described TOSA 2210, and the LD 160 oscillates light having a wavelength λ2.

  The reflection mirror 2211 of the TOSA 2320 allows light of wavelength λ1 to pass and reflects light of wavelength λ2. The reflection mirror 2211 of the TOSA 2320 is provided at a position that allows the optical signal emitted from the TOSA 2310 to pass through and a position that reflects the optical signal oscillated from the LD 160 of the TOSA 2320.

  As a result, the optical signal having the wavelength λ1 emitted from the TOSA 2310 and passing through the reflecting mirror 2211 of the TOSA 2320 and the optical signal having the wavelength λ2 oscillated from the LD 160 of the TOSA 2320 and reflected by the reflecting mirror 2211 are overlapped and multiplexed. . The TOSA 2320 outputs the multiplexed optical signals (λ1, λ2) to the TOSA 2330.

  The TOSA 2330 and the TOSA 2340 have the same configuration as the TOSA 2320 except for the wavelength of the optical signal oscillated by each LD 160. The TOSA 2330 multiplexes the optical signal having the wavelength λ3 with the optical signals (λ1, λ2) emitted from the TOSA 2320, and emits the multiplexed optical signals (λ1 to λ3) to the TOSA 2340. The TOSA 2340 multiplexes the optical signal having the wavelength λ4 with the optical signals (λ1 to λ3) emitted from the TOSA 2330, and emits the multiplexed optical signals (λ1 to λ4) to the reflecting member 2350.

  The reflecting member 2350 has a configuration in which the LD 160 is omitted from the above-described TOSA 2210. The reflection member 2350 totally reflects the optical signal (λ1 to λ4) emitted from the TOSA 2340 at a right angle by the reflection mirror 2211 and emits the light signal to the side opposite to the wiring substrate 110. As a result, the WDM oscillator 2300 can emit an optical signal obtained by multiplexing optical signals having wavelengths λ1 to λ4.

  According to the WDM oscillator 2300 according to the third embodiment of the present invention, by reducing the size of each of the optical subassemblies 100, it is possible to mount a plurality of optical subassemblies 100 in an array at a high density. Can be miniaturized. Further, since the optical subassemblies 100 can be mounted in an array at high density, the error for each wavelength component of the optical signal due to the optical path length difference for each optical subassembly 100 can be reduced.

  In addition, since the LD 160 and the lens member 170 of the TOSA 2310, 2320, 2330, and 2340 can be accurately positioned with respect to the wiring substrate 110, the optical signals of the respective wavelength components can be multiplexed with high accuracy. Therefore, it is possible to output a highly accurate wavelength multiplexed optical signal.

Example 4
FIG. 24 is a schematic plan view illustrating a receiving circuit according to the fourth embodiment of the present invention. The receiving circuit 2400 according to the fourth embodiment of the present invention branches an optical signal that has been subjected to differential phase modulation (DPSK), and causes a delay of one symbol to interfere with one of the branched signals. This is an example in which the optical subassembly 100 according to the first exemplary embodiment of the present invention is applied to a receiving circuit.

  As shown in FIG. 24, the receiving circuit 2400 includes a Mach-Zehnder type including a total reflection mirror 2410, a half mirror 2420, a total reflection mirror 2430, a total reflection mirror 2440, a half mirror 2450, a PD 2460, and a PD 2470. It is an interferometer. Each element included in the receiving circuit 2400 has a configuration in which the optical subassembly 100 is deformed, and the respective wiring boards 110 are integrally configured.

  Total reflection mirror 2410 reflects the optical signal that has been subjected to differential phase modulation, and outputs the reflected optical signal to half mirror 2420. The half mirror 2420 reflects a part of the optical signal emitted from the total reflection mirror 2410 and emits it to the total reflection mirror 2430, and passes a part of the optical signal emitted from the total reflection mirror 2410 to pass the half mirror 2450. To exit.

  Total reflection mirror 2430 and total reflection mirror 2440 configure a bypass path that bypasses the optical signal emitted from half mirror 2420 and gives a delay of one symbol. Total reflection mirror 2430 and total reflection mirror 2440 give the optical signal emitted from half mirror 2420 a delay and emit it to half mirror 2450.

  The half mirror 2450 reflects a part of the optical signal emitted from the half mirror 2420 and emits it to the PD 2460, passes a part of the optical signal emitted from the half mirror 2420 and emits it to the PD 2470. The half mirror 2450 reflects a part of the optical signal emitted from the total reflection mirror 2440 and emits it to the PD 2470, passes a part of the optical signal emitted from the total reflection mirror 2440 and emits it to the PD 2460. .

  PD 2460 and PD 2470 each receive an optical signal emitted from half mirror 2450 and convert it into an electrical signal. The optical signal received by the PD 2460 and the optical signal received by the PD 2470 have a normal phase / reverse phase relationship. The reception circuit 2400 can demodulate the optical signal subjected to the differential phase modulation by receiving the balanced optical signals in the normal phase / reverse phase relationship.

  FIG. 25 is a front sectional view showing a receiving circuit according to the fourth embodiment of the present invention. 25 is a cross-sectional view taken along the line AA 'of FIG. As shown in FIG. 25, the total reflection mirror 2410 has the same configuration as the reflection member 2350 (see FIG. 23) described above. Although not shown, the total reflection mirror 2430 and the total reflection mirror 2440 cause the reflection mirror 2211 to reflect the light emitted in parallel with the wiring substrate 110 at a right angle while being parallel to the wiring substrate 110 in the reflection member 2350 described above. This is a modified configuration.

  The half mirror 2420 and the half mirror 2450 have a configuration in which the above-described TOSA 2210 includes a half mirror 2510 instead of the reflection mirror 2211 and omits the LD 160. The PD 2470 has the same configuration as the above-described ROSA 2220 (see FIG. 22). Although not shown, the PD 2460 has the same configuration as the ROSA 2220 described above.

  According to the receiving circuit 2400 according to the fourth embodiment of the present invention, the modification of the configuration of the optical subassembly 100 is applied to each element of the Mach-Zehnder interferometer, so that the elements of the Mach-Zehnder interferometer can be mounted with high density. can do. For this reason, a small Mach-Zehnder interferometer can be configured.

  In addition, since all the elements of the total reflection mirror 2410, the half mirror 2420, the total reflection mirror 2430, the total reflection mirror 2440, the half mirror 2450, the PD 2460, and the PD 2470 can be accurately positioned with respect to the wiring board 110, a highly accurate Mach-Zehnder type An interferometer can be constructed. For this reason, the optical signal subjected to differential phase modulation can be demodulated with high accuracy.

  In each of the above-described examples, the example in which the optical subassembly 100 according to the first embodiment of the present invention is applied has been described. However, the optical subassembly according to the second embodiment of the present invention is applied to each of the above-described examples. 100 can also be applied.

  As described above, according to the optical subassembly manufacturing method and the optical subassembly according to the present invention, it is possible to reduce the cost of the optical subassembly while reducing the size of the optical subassembly. Also, by applying the optical subassembly manufacturing method and the optical subassembly according to the present invention to an OSA array, an optical interconnect device, a WDM oscillator, and a receiving circuit, the OSA array, the optical interconnect device, the WDM oscillator, and the reception Circuit manufacturing time can be shortened, miniaturized, and highly accurate.

  As described above, the optical subassembly manufacturing method and the optical subassembly according to the present invention are useful for an optical interconnect of a server system or a network device, an optical interconnect device, a WDM oscillator, a receiving circuit, and the like. Suitable when high density mounting of optical subassemblies is required.

  The following additional notes are disclosed with respect to the embodiment described above.

(Appendix 1) A forming step of forming a connection electrode and a convex refractory glass on a wiring board by determining relative positions of each other;
A positioning step of positioning and connecting the photoelectric conversion element on the connection electrode;
An arrangement step of arranging a low melting point glass having a lower melting point than the high melting point glass on the high melting point glass,
The projection has a shape matching the high melting point glass and a lens portion, and the relative position between the projection and the optical axis of the lens portion is determined according to the relative position between the connection electrode and the high melting point glass. Fixing the projecting portion of the lens member placed and fixed on the low-melting glass,
In the fixing step, the lens member is positioned with respect to the high melting point glass by melting the low melting point glass.

(Additional remark 2) The said photoelectric conversion element has a photoelectric conversion part and the electrode connected to the said photoelectric conversion part, and the relative position of the optical axis of the said photoelectric conversion part and the said electrode is decided to the predetermined position. And
In the positioning step, the second low melting point glass having a lower melting point than the wiring electrode is disposed on the wiring electrode, and the electrode of the photoelectric conversion element is disposed on the second low melting point glass. Fixing process, and
The method of manufacturing an optical subassembly according to appendix 1, wherein, in the fixing step, the photoelectric conversion element is positioned with respect to the wiring electrode by melting the second low-melting glass.

(Appendix 3) In the forming step, the refractory glass is formed in an annular shape surrounding the connection electrode,
The protrusion of the lens member is formed in an annular shape that matches the high melting point glass,
2. The method of manufacturing an optical subassembly according to appendix 1, wherein in the fixing step, the photoelectric conversion element is hermetically sealed by the wiring substrate, the high melting point glass, the low melting point glass, and the lens member.

(Appendix 4) In the forming step, a plurality of the high melting point glasses are scattered on the wiring substrate,
In the arrangement step, the plurality of low-melting glasses are arranged on the plurality of high-melting glasses,
2. The method of manufacturing an optical subassembly according to appendix 1, wherein the lens member has a plurality of the protrusions that match the plurality of high melting point glasses.

(Additional remark 5) The 2nd formation process which forms the cyclic | annular high melting point glass surrounding the said connection electrode on the said wiring board,
A second disposing step of disposing a third low melting point glass having a melting point lower than that of the second high melting point glass on the second high melting point glass,
The lens member further includes an annular second protrusion matched to the second refractory glass,
In the fixing step, after positioning the lens member, the second low melting glass is melted to join the second high melting glass and the second protrusion, and the wiring board, the second high melting point The method of manufacturing an optical subassembly according to appendix 4, wherein the photoelectric conversion element is hermetically sealed with glass, the second low-melting glass, and the lens member.

(Additional remark 6) The said projection part of the said lens member has the light transmittance which permeate | transmits a laser,
2. The method of manufacturing an optical subassembly according to claim 1, wherein, in the fixing step, the low-melting glass is melted by irradiating the low-melting glass with a laser through the protrusion.

(Appendix 7) In the forming step, the high melting point glass and the low melting point glass are formed in an annular shape surrounding the connection electrode,
The protrusion of the lens member is formed in an annular shape that matches the high melting point glass,
7. The light according to appendix 6, wherein, in the fixing step, the low-melting glass is irradiated with the laser through the protrusion while rotating the laser irradiation device in an annular shape matching the low-melting glass. Subassembly manufacturing method.

(Supplementary note 8) The method of manufacturing an optical subassembly according to supplementary note 6, wherein the laser is a femtosecond laser.

(Additional remark 9) The said formation process WHEREIN: The said connection electrode and the said high melting point glass are formed by lithography, The manufacturing method of the optical subassembly of Additional remark 1 characterized by the above-mentioned.

(Appendix 10) The high melting point glass and the low melting point glass are silica glasses, and the low melting point glass has an melting point lower than that of the high melting point glass by adding impurities to the silica glass. The manufacturing method of the optical subassembly as described in 2.

(Appendix 11) A connection electrode formed on the wiring board;
A convex refractory glass formed on the wiring board by determining a relative position with the connection electrode;
A photoelectric conversion element positioned and connected on the connection electrode;
A low-melting glass disposed on the high-melting glass and having a lower melting point than the high-melting glass;
The projection has a shape matching the high melting point glass and a lens portion, and the relative position between the projection and the optical axis of the lens portion is determined according to the relative position between the connection electrode and the high melting point glass. A lens member that is disposed and fixed on the low-melting-point glass.
The optical subassembly according to claim 1, wherein the lens member is positioned with respect to the high melting point glass by melting the low melting point glass.

(Supplementary note 12) The high melting point glass is formed in an annular shape surrounding the connection electrode,
The protrusion of the lens member is formed in an annular shape that matches the refractory glass,
The optical subassembly according to appendix 11, wherein the photoelectric conversion element is hermetically sealed by the wiring board, the high melting point glass, the low melting point glass, and the lens member.

(Additional remark 13) The mirror which reflects the light radiate | emitted from the said photoelectric conversion element to a predetermined optical path, or reflects the light radiate | emitted from the said predetermined optical path to the optical axis of the said photoelectric conversion element, is further provided.
The optical subassembly according to appendix 11, wherein an optical axis of the lens portion of the lens member coincides with the predetermined optical path.

(Supplementary note 14) The optical subassembly according to supplementary note 13, wherein the photoelectric conversion element is a light emitting element that oscillates an optical signal, and the optical signal oscillated by the photoelectric conversion element is emitted from the lens unit;
The optical subassembly according to appendix 13, wherein the photoelectric conversion element is a light receiving element that receives an optical signal and converts the optical signal into an electrical signal, and receives the optical signal emitted from the optical subassembly;
An optical interconnect device comprising:

(Supplementary note 15) A plurality of optical subassemblies according to supplementary note 13,
Each of the photoelectric conversion elements of the plurality of optical subassemblies is a light emitting element that oscillates optical signals having different wavelengths.
Each mirror of the plurality of optical subassemblies reflects an optical signal oscillated by the light emitting element of the corresponding optical subassembly to the predetermined optical path, and passes an optical signal emitted from another optical subassembly. And a wavelength selective mirror that multiplexes with the reflected optical signal.

(Supplementary note 16) A reception circuit that includes two optical subassemblies according to supplementary note 13, and that receives and demodulates an optical signal subjected to differential phase modulation,
The photoelectric conversion element is a light receiving element that receives an optical signal and converts it into an electrical signal,
The receiving circuit, wherein the two optical subassemblies receive a normal phase signal and a negative phase signal included in the optical signal in a balanced manner.

DESCRIPTION OF SYMBOLS 100 Optical subassembly 110 Wiring board 120 Connection electrode 130 Solder bump 140,1610 High melting glass 150,1620 Low melting glass 160 LD
161 Light emitting portion 162 Electrode 163, 173 Optical axis 170 Lens member 171, 1630 Protrusion portion 172 Lens portion 710, 1010 Photoresist 2100 OSA array 2110 Guide pin 2120 Ferrule 2130 Optical fiber 2200 Optical interconnect device 2210, 2310, 2320, 2330 , 2340 TOSA
2211, 222 Reflection mirror 2220 ROSA
2300 WDM oscillator 2350 Reflective member 2400 Receiving circuit 2410, 2430, 2440 Total reflection mirror 2420, 2450 Half mirror

Claims (10)

Forming a connection electrode and a convex refractory glass on a wiring board by deciding relative positions of each other;
A positioning step of positioning and connecting the photoelectric conversion element on the connection electrode;
An arrangement step of arranging a low melting point glass having a lower melting point than the high melting point glass on the high melting point glass,
The projection has a shape matching the high melting point glass and a lens portion, and the relative position between the projection and the optical axis of the lens portion is determined according to the relative position between the connection electrode and the high melting point glass. Fixing the projecting portion of the lens member placed and fixed on the low-melting glass,
In the fixing step, the lens member is positioned with respect to the high melting point glass by melting the low melting point glass. The photoelectric conversion element includes a photoelectric conversion unit and an electrode connected to the photoelectric conversion unit, and a relative position between the optical axis of the photoelectric conversion unit and the electrode is determined at a predetermined position,
In the positioning step, the second low melting point glass having a lower melting point than the wiring electrode is disposed on the wiring electrode, and the electrode of the photoelectric conversion element is disposed on the second low melting point glass. Fixing process, and
2. The method of manufacturing an optical subassembly according to claim 1, wherein in the fixing step, the photoelectric conversion element is positioned with respect to the wiring electrode by melting the second low melting point glass. In the forming step, the refractory glass is formed in an annular shape surrounding the connection electrode,
The protrusion of the lens member is formed in an annular shape that matches the high melting point glass,
2. The method of manufacturing an optical subassembly according to claim 1, wherein in the fixing step, the photoelectric conversion element is hermetically sealed by the wiring substrate, the high melting point glass, the low melting point glass, and the lens member. In the forming step, a plurality of the high melting point glasses are scattered on the wiring board,
In the arranging step, a plurality of the low melting point glasses are respectively arranged on the plurality of high melting point glasses,
2. The method of manufacturing an optical subassembly according to claim 1, wherein the lens member has a plurality of the protrusions that match the plurality of high melting point glasses. 3. A second forming step of forming an annular second refractory glass surrounding the connection electrode on the wiring board;
A second disposing step of disposing a third low melting point glass having a melting point lower than that of the second high melting point glass on the second high melting point glass,
The lens member further includes an annular second protrusion matched to the second refractory glass,
In the fixing step, after positioning the lens member, the second low melting glass is melted to join the second high melting glass and the second protrusion, and the wiring board, the second high melting point 5. The method of manufacturing an optical subassembly according to claim 4, wherein the photoelectric conversion element is hermetically sealed with glass, the second low-melting glass, and the lens member. The protrusion of the lens member has a light transmitting property to transmit a laser,
2. The method of manufacturing an optical subassembly according to claim 1, wherein in the fixing step, the low-melting glass is melted by irradiating the low-melting glass with a laser through the protrusions. In the forming step, the high melting point glass and the low melting point glass are formed in an annular shape surrounding the connection electrode,
The protrusion of the lens member is formed in an annular shape that matches the high melting point glass,
The laser beam is irradiated to the low-melting-point glass through the protrusion while rotating the laser irradiation device in an annular shape matching the low-melting-point glass in the fixing step. Manufacturing method of optical subassembly.   2. The method of manufacturing an optical subassembly according to claim 1, wherein, in the forming step, the connection electrode and the refractory glass are formed by lithography. A connection electrode formed on the wiring board;
A convex refractory glass formed on the wiring board by determining a relative position with the connection electrode;
A photoelectric conversion element positioned and connected on the connection electrode;
A low-melting glass disposed on the high-melting glass and having a lower melting point than the high-melting glass;
The projection has a shape matching the high melting point glass and a lens portion, and the relative position between the projection and the optical axis of the lens portion is determined according to the relative position between the connection electrode and the high melting point glass. A lens member that is disposed and fixed on the low-melting-point glass.
The optical subassembly according to claim 1, wherein the lens member is positioned with respect to the high melting point glass by melting the low melting point glass. The refractory glass is formed in an annular shape surrounding the connection electrode,
The protrusion of the lens member is formed in an annular shape that matches the refractory glass,
The optical subassembly according to claim 9, wherein the photoelectric conversion element is hermetically sealed by the wiring board, the high melting point glass, the low melting point glass, and the lens member.

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